ToA Purple Chance and Loot Probability
Model ToA purple odds, team share, target-item probability, raid milestones, expected value, and GP per hour.
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Use a Verified Personal or Team Chance
The OSRS ToA Loot Calculator accepts a verified purple chance rather than inventing a simplified invocation formula.
Jagex's published mechanics state that an individual cannot accumulate more than 64,000 total raid points and needs at least 1,500 points to be eligible for a unique.
Team Chance and Personal Share
A team purple chance is not automatically your personal chance. Multiply it by your expected contribution share.
Use 100% personal share for solo raids.
Cumulative Purple Chance
For personal purple probability (p) across (n) independent raids:
P(at least one purple) = 1 - (1 - p)^nTarget Item
Multiply personal purple probability by the selected item's conditional share of the unique table.
Expected Value
Purple EV equals expected purples multiplied by average purple value. Add common loot, subtract raid costs, and divide by total hours for GP per hour.
Probability Is Not a Guarantee
Expected purples can be fractional. A player can receive multiple early purples or remain dry far beyond the expected count.
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Frequently Asked Questions
- Does invocation level alone determine exact purple chance?
- No. Raid points and performance matter, so use a verified chance for the actual setup.
- What is the individual points cap?
- Jagex published a maximum of 64,000 individual total points for a raid.
- What is the minimum eligibility threshold?
- Jagex published a minimum of 1,500 total points to be eligible for a unique.
Last updated 7/18/2026